@Precarious Armada, you can hear the other 11 parts in the song, more or less. This video just doesn’t show all 12 at once because they’re all played by the same guy on the same cello and they chose not to do the video magic for it.

I hope the snowy/winter scenes were fake, because good-quality musical instruments should NOT be exposed to the cold, especially not wooden ones. This was drilled into my head in high school–cold air can crack a wooden instrument, thereby necessitating an expensive repair or even a replacement. But, as for the video itself, this cellist is very talented, and he did a really interesting twist on a traditional Christmas carol.

@Anonymous, he has multiple cellos, including one just for situations like this. It’s his “stunt cello,” also known as “Jackie.” (According to the Piano Guys website). But nothing was done in front of a green screen; those are all real places.